This invention relates generally to valve assemblies, and more particularly to fuel injectors having an electrically actuated valve positioned in a middle portion of the injector body.
Increasingly, fuel injectors are being equipped with direct control needle valves that are controlled in operation by a separate valve assembly to allow for independent control over injection characteristics, such as injection pressure and timing. Engineers have determined that for many applications it is beneficial to position the needle control valve assembly in close proximity to the direct control needle valve member. One example of such a fuel injector is disclosed in U.S. Pat. No. 5,697,342, which issued to Anderson et al. on Dec. 16, 1997. However, when the valve assembly is positioned in this more central portion of the fuel injector, it is problematic finding sufficient room to route fluid passages within the fuel injector around or through the valve assembly electrical actuator. This problem often results in undesirable compromises to accommodate the needed fluid passages around the electrical actuator, while maintaining performance requirements for the valve.
The present invention is directed to overcoming one or more of the problems as set forth above.
In one aspect of the present invention, a fuel injector includes an injector body that has a body centerline and provides a middle portion separating an upper portion from a lower portion. The injector body defines a fluid passage extending between the upper portion and the lower portion through the middle portion. An electrical actuator is attached to the injector body and is positioned in the middle portion. The electrical actuator has an actuator centerline. A valve member is positioned in the middle portion and is operably coupled to the electrical actuator. The valve member has a first position in which the fluid passage is open, and a second position in which the fluid passage is at least partially closed. The actuator centerline is oriented at an angle, which is greater than zero, with respect to the body centerline.
In another aspect of the present invention a valve assembly for positioning in a casing component includes a body component that has a body centerline and a top face that is separated from a bottom face by an annular side surface. The body component defines a fluid passage that extends from the top face to the bottom face. The top face and the bottom face provide at least one planar contact surface that is substantially perpendicular to the body centerline. An electrical actuator is attached to the body component away from the fluid passage. A valve member having a valve centerline oriented at an angle, greater than zero, with respect to the body centerline, is operably coupled to the electrical actuator, and is at least partially positioned in the body component. The valve member has a first position in which the fluid passage is open, and a second position in which the fluid passage is at least partially closed.
In yet another aspect of the present invention, a method of injecting fuel includes routing high pressure fuel to a nozzle chamber through a high pressure passage that is at least partially defined by a valve body component, but away from an electrical actuator that is attached to the valve body component. A needle valve member is moved to an open position, at least in part by relieving fluid pressure on a closing hydraulic surface of the needle valve member. The needle valve member is moved to a closed position, at least in part by resuming fluid pressure on the closing hydraulic surface of the needle valve member. At least one of the moving steps includes a step of energizing the electrical actuator to move a control valve member along a line oriented at an angle, greater than zero, with respect to a centerline of the needle valve member.